This invention relates generally to automatic controls for prime mover steering systems, and more particularly concerns an automatic steering system for a device such as a farm tractor.
In operating a prime mover such as a farm tractor in a field, the operator faces the tedious and tiring task of accurately guiding the prime mover and any pulled or operated implements with great precision along a predetermined path. For example, in plowing it is necessary to steer the pulling farm tractor so that evenly spaced furrows are created adjacent those furrows created in the last plow pass. The careful attention of the plowman is required in steering the tractor, yet he must also attend to adjusting tractor speed, plow depth and other variables.
To reduce this burden on the prime mover operator, a number of automatic steering devices have been offered to assist in tractor steering or to take over these steering jobs entirely. Until the present time, however, these devices have been more numerous than successful, and it is still the common practice to use manual steering methods to steer farm tractors while plowing, seeding, cultivating or otherwise treating field crops.
It is accordingly a general object of the present invention to provide a commercially attractive automatic steering mechanism for a prime mover such as a farm tractor.
A more specific object is to provide an automatic steering mechanism which will follow a previously formed furrow or other predetermined path in a field with consistency and accuracy. An ancillary object is to provide such an automatic steering mechanism which will accurately follow a predetermined route of travel at normal operating speeds without hunting or over-controlling.
Yet another object is to provide an automatic steering mechanism for a prime mover which is reliable and rugged in operation. A related object is to provide such an automatic steering mechanism which can be offered at a commercially attractive price.
Another object is to provide an automatic steering mechanism of the type described having a value in which the position of the steering gear and the position of the path or furrow follower are sensed, and in which these position sensing activities are used to produce a steering output signal which is reliable and precise.
A related object of the invention is to provide an automatic steering mechanism of the type described having a valve or similar mechanism which provides steering input to a fluid power steering circuit and which also operates to raise and lower a furrow follower mechanism.
It is yet another object to provide such an automatic steering mechanism in which a hydraulic valve or similar mechanism can be positioned by a path or furrow follower device to cause the prime mover to be automatically steered in a direction following the path or furrow. Alternatively, the valve is effectively removed from the circuit when the furrow follower is raised to an inoperative position.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.